Zinc-air cells are not turned on till a tape seal is removed from the positive side of the battery. This side contains tiny holes thru which air enters to initiate activation.

In the majority of situations, the zinc-air cells last longer than their mercury opposite numbers. Hearing aid batteries have a comparatively flat discharge rate, and the battery’s capacity is rated in milliampere hours ( mAh ). If this drain of a hearing aid is understood, an estimation of the anticipated life of the battery can be figured out by dividing the battery’s capacity by the present drain measured in milliamperes.